\ 
eG REPORT OF THE COMMISSIONER OF FISHERIES. 
The parasites of fishes. By Edwin Linton, Ph. D., professor of biology, Washing- 
ton and Jefferson College. 
Physiology of the lateral-line organs of fishes. By George H. Parker, Ph. D., 
assistant professor of zoology, Harvard University. 
A synopsis of the annelids of the Woods Hole region. By J. Percy Moore, Ph. D., 
instructor’in zoology, University of Pennsylvania. 
The total number of investigators who availed themselves of the 
privileges of the laboratory during the summer was 30, the greatest 
number at any one time being 20. These men represented two goy- 
ernment departments and 16 educational institutions, ranging from 
Alabama to Vermont and west to Illinois. The nature of their inves- 
tigations is indicated below: 
Artificial sea waters as tested in aquaria.—At the suggestion of Mr. W. de C. Ravenel, 
representative of the Bureau of Fisheries at the St. Louis Exposition, experiments 
were made under authority of the Secretary of Agriculture and of the Commissioner 
of Fisheries, to determine, if possible, how far it may be practicable to make 
artificial sea water capable of sustaining marine plant and animal life. This work 
was conducted by Dr. Rodney H. True, physiologist of the Department of Agricul- 
ture, assisted by Mr. W. O. Richtman, of the Department of Agriculture, and Mr. 
Grant Smith, graduate student of Harvard University. 
Experiments were made with artificial sea water prepared in two ways: (1) By 
dissolving in distilled water the complete salts of the sea, obtained by evaporation; 
(2) by dissolving in distilled water chemically prepared salts in proportions deter- 
mined by analysis. The Challenger analyses by Dittmar were used. Aquaria were 
provided with artificial waters prepared according to each of these methods and with 
sea water dipped from the current at the end of the wharf at the Woods Hole station. 
Two sets of such aquaria were prepared: (1) Standing aquaria kept at constant salt 
content by the addition of fresh water; (2) aquaria through which a small stream of 
water was kept flowing, providing thereby a system of closed circulation. 
Aquaria thus prepared were stocked with both plant and animal life, the plants 
most used being green forms common at Woods Hole—Cladophora, Enteromorpha, 
Ulva, and Aghardiella tenera. Many types of animal life were studied, including 
especially sea anemones (Metridium), starfish (Asterias), medusee (Gonionemus), 
squid (Loligo), and fish (silversides, scup, pipe-fish, ete.). The general result may 
be stated as follows: Sea anemones seemed to flourish in all the media during the 
period under observation. Starfish survived and behaved normally in the water 
made from evaporated sea salt, but in some cases showed symptoms of injury in the 
synthetic solution. Gonionemus survived for several weeks in both solutions, but 
appeared to suffer from its contact with other forms of life in the aquaria. The squid 
could not be made to survive for more than a few days in any medium, artificial or 
natural. It died in the synthetic solution in less than ten minutes, with violent 
symptoms, but survived in the other artificial solution as long as in the natural sea 
water. Fish, including delicate forms like Menidia, seemed in all cases to live as well 
in the artificial solutions as in the natural. Severa] other forms of fish and inverte- 
brates were tested in various ways, with the general result that the artificial solution 
made from the salt obtained by evaporation permitted survival to a degree not clearly 
different from that seen in sea water. The synthetic artificial solution seemed equally 
favorable to most forms, but distinctly less so to a few. 
The edible lamellibranchs as a source of infection.—This research was conducted by 
Dr. George Wilton Field, of the Massachusetts State Board of Health, assisted by Dr. 
C. A. Fuller, and involved a study of the relations between shellfish and sewage 
bacteria, with experiments designed to answer the following questions: (1) Are 
